Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 950

June 5, 201710 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 5, 2017, 1:30 PM CDT for 10 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 5, 2017, 1:30 PM CDT (18:30 UTC)
Expired
Jun 5, 2017, 4:00 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Brooks County, TX, Cameron County, TX, Duval County, TX, Hidalgo County, TX, Jim Hogg County, TX, Jim Wells County, TX, Kenedy County, TX, Kleberg County, TX, Starr County, TX, Willacy County, TX

The radar

The Corpus Christi radar (KCRP), 129 km from the middle of the area, began a volume at 18:34 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 6.5 hours before the alert went out and 135 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 2017-06-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1436 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 12:00Z on 2017-06-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1436 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
944 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.7

Open this sounding in Storm Lab

The text

As transmitted.

195 
ACUS11 KWNS 051830
SWOMCD
SPC MCD 051830 
TXZ000-052100-

Mesoscale Discussion 0950
NWS Storm Prediction Center Norman OK
0130 PM CDT Mon Jun 05 2017

Areas affected...Deep South TX

Concerning...Severe potential...Watch possible 

Valid 051830Z - 052100Z

Probability of Watch Issuance...40 percent

SUMMARY...Large hail and damaging wind gusts possible as
thunderstorm coverage increases this afternoon. Convective trends
across the region will be monitored for possible watch issuance.

DISCUSSION...Strong instability continues to build across deep south
TX with temperatures already in the mid to upper 90s and dewpoints
in the upper 60s to low 70s. Recent mesoanalysis estimates MLCAPE is
around 2500 J/kg across much of the region, with little to no
convective inhibition remaining. This erosion of the convective
inhibition sample on the 12Z BRO and CRP soundings is further
evidenced by the increasing cu field noted on recent visible
imagery.

Modest forcing for ascent (associated with a weak perturbation
rounding the western periphery of the upper low) will continue to
interact with this unstable environment over the next few hours,
likely supporting an increase in both thunderstorm coverage and
strength. Additionally, slightly stronger mid-level flow through the
base of the upper low will contribute to stronger bulk shear and the
potential for updraft organization. These stronger, more organized
storms will have the potential to produce large hail and damaging
winds gusts. Limited spatial extent of the threat precludes higher
watch probabilities but convective trends across the region will be
monitored closely.

..Mosier/Guyer.. 06/05/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...CRP...BRO...

LAT...LON   26799915 27559900 27849822 27509747 26189720 25959747
            26359882 26799915

Nearby

Mesoscale Discussions in Texas, 2017Every mesoscale discussion in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.